This application is based on and hereby claims priority to German Application No. 10064108.3 filed on Dec. 21, 2000 in Germany, the contents of which are hereby incorporated by reference.
The invention relates to a placement head and also a placement system for a placement apparatus for placing components in a placement plane, which has at least one gripper for picking up and/or putting down the components.
In conventional automatic placement machines having a plurality of placement heads which each populate a placement plane with components from different sides of the placement plane, there is a problem in that the placement heads cannot simultaneously populate the placement plane. This results in a risk of collision of placement heads simultaneously effecting placement, which exists whenever the placement heads have mutually overlapping movement regions. An attempt has previously been made to solve this problem by the placement heads only being used one after the other to populate the placement plane. In this case, by way of example, the placement plane is populated by one placement head, while components are picked up from a feed device by another placement head. In this case, however, the placement performance of the automatic placement machine essentially depends on the placement performance of a single placement head and is thus greatly limited.
One potential application of the invention is based on the object of specifying a placement head and also a placement system by which faster, more flexible and more reliable placement is possible.
One aspect of the invention provides a placement head for a placement apparatus for placing components in a placement plane, which has at least one gripper for picking up and/or for puffing down the components in a placement position of the placement head. In this case, the placement position is that position of the placement head in which the gripper is able to pick up or put down a component. The gripper is fitted in an edge region of the placement head in such a way that, in the case of a projection of the placement head onto the placement plane, the image of the gripper situated in the placement position essentially does not project from the image of the placement head. This ensures that the gripper situated in the placement position is arranged near the edge region of the placement head and the gripper, in the direction in which the placement head can move toward a lateral boundary of the placement plane, does not substantially project beyond the placement head. As a result, the placement plane can be populated essentially over the whole area with the placement head.
In the case of a placement head having a plurality of grippers, the latter are fitted on the placement head, for example in a rotationally symmetrical manner, and their axis of rotation is inclined with respect to the placement plane of the automatic placement machine. The effect achieved by the inclination of the axis of rotation is that the structural space required for mounting a corresponding rotationally symmetrical holder for the grippers above the placement plane does not have to extend in the direction perpendicular to the placement plane beyond the limits of the rotationally symmetrical holder. The grippers can then be arranged, with respect to the rotationally symmetrical holder, with the same angle of inclination which the axis of rotation forms with the placement plane of the automatic placement machine, with the result that a gripper situated in the placement position is arranged perpendicular to the placement plane. This makes it possible to minimize the structural space of the placement head that is required in the vertical direction above the placement plane.
The placement head can also be designed like a turret head. In this case, the rotationally symmetrical holder for the grippers has a turret form. The axis of rotation of this turret may in this case be inclined or perpendicular with respect to the placement plane of the automatic placement machine.
One aspect of the invention also provides a placement system having at least two elongate supports, by which a respective placement head is guided movably in a respective first movement region. In this case, the supports are arranged facing one another above the placement plane. The configuration of the placement heads makes it possible for the latter to be moved simultaneously within the respective first movement region, with the result that the placement plane can be simultaneously populated in the first movement regions by the placement heads. Since the placement heads are designed in such a way that the grippers, in the placement position of the respective placement head, are arranged directly in the edge region of the placement head and essentially such that they do not project from said placement head, a plurality of placement heads can be moved toward one another in such a way that they cannot touch one another within their first movement region, but the remaining movement region above the placement plane, which region is not covered by the respective first movement regions, is very small. In particular, except for a second movement region whose width essentially corresponds to the diameter of a gripper, the placement heads can populate the placement plane simultaneously and independently of one another. The second movement region whose width essentially corresponds to the diameter of a gripper must be sequentially populated by the placement heads in order to rule out possible collisions between the placement heads.
A placement head and also a placement system which is provided, with the placement head in which a gripper is fitted in an edge region of the placement head, so that it terminates for example flush with the edge region of the placement head or projects only slightly from this edge region beyond the placement head.
Using such a placement head or placement system, in a placement plane of an automatic placement machine on which there are boundary areas that are vertical with respect to the placement plane, the entire placement plane can be populated except for a residual region whose width corresponds to half the diameter of a gripper of the placement head. In this case, the residual region is the region yielded on the placement plane between the vertical boundary area directly adjoining the placement plane and the region which can be populated by the placement head.
If a plurality of placement heads are used in a placement system, then a vertical boundary area is defined for example in the limits of the movement region of one of the two placement heads. The respective other placement head must not exceed the limits of this movement region since otherwise there is a risk of collision with the other placement head. Since the grippers are arranged on the placement heads in a respective edge region of the placement head in a manner terminating with the latter or projecting slightly from said edge region, that movement region which, in the case of simultaneous and independent operation of the two placement heads, cannot be used, in order to avoid collisions, corresponds to a movement region whose width essentially corresponds to the diameter of a gripper. This second movement region can only be sequentially populated by the placement heads.
By virtue of the simultaneous placement using, for example, two or more placement heads, the oscillations in the placement system are minimized since it is possible to carry out simultaneously mutually corresponding movements in opposite directions. If a plurality of printed circuit boards are arranged next to one another on the placement plane, it is possible to effect placement simultaneously and independently without limitations, since the second movement region, in which the placement heads should operate sequentially, for example in the case of two printed circuit boards arranged next to one another, is covered by the transport mechanism between the printed circuit boards, which is not populated.